Process of manufacturing leather



March 25, 1930; J. P. TOOLE 1,752,042

PROCESS OF MANUFACTURING LEATHER Filed Dec 15, 1928 INVENTOR av XSM ATTORNEY-S Patented Mar. 25, 1930 UNITED STATES PATENT OFFICE JOHN P. TOOLE, OF DETROIT, MICHIGAN, ASSIGNOR T0 CARL E. SCHMIDT & COMPANY, OF DETRQIT, MICHIGAN, A CORPORATION OF MICHIGAN PROCESS OF MANUFACTURING LEATHER Application filed Deceiiibenfl, 1928. Serial in. 320,354.

The invention relates to the manufacture of leather and particularly to the stretching and drying of the skins after the curing of the same. The present invention is in the nature of an improvement upon a process heretofore used and generally described in the patent to Carl E. Schmidt, No. 1,118,813 issued November 24, 1914. The process forming the subject matter of the said patent consists essentially in coating the grain surface of the skin with a mucilaginous substance and placing it face downward upon a drying board and then setting out the skin on said board by stretching out the thick portions and contracting or working them in to the thin portions so as to obtain a more nearly uniform thickness in all portions of the skin and also to firmly attach the same to the drying board; then permitting the skin to dry upon the board and finally stripping it from the board and washing off the film of adhesive on the surface thereof.

The process just described is one which has been very extensively used in the manufacture of leather, but it has been found that for certain grades of leather and particularly for certain finishes the use of the adhesive or mucilaginous substance is objectionable. An-

other process also extensively used is to attach the skins to the board by tacking the marginal portions. thereof. This is objectionable first in that it destroys a considerable portion ofthe area of the leather by cutting the same with the tacks, second, the skin is not held as firmly to the board during drying and consequently is not as uniformly distributed.

To retain the advantages of the pasting process while avoiding the detrimental effect incidental to the use of the adhesive, I'have devised a novel process as more fully hereinafter set forth.

In the drawing I have illustrated in plan view a drying board showing the manner of mounting the skin thereon.

With my improved process after the skins have been cured and are ready formounting on the drying boards, they are removed from a water bath and are placed grain face downward upon the board. The marginal portions of the skin are then firmly attached to and sealed against the board without the use of tacks or anything else which will injure the marginal portions. Preferabl I accomplish this by the use of a holding abric which is first saturated with a suitable adhesive and then placed over the back of the skin so as to extend beyond the margin thereof and on to the outer portions of the board. The skin may then be worked out in the usual manner which will also so firmly attach the fabric to the board that it will hold the skin in position until dry. Inasmuch as it is only the marginal portions that need to be held, I preferably use a plurality of strips of the fabric arranged to cover the margin of the skin instead of a continuous sheet covering the whole skin. Thus as shown in the drawing, A represents the drying board, B the skin placed thereon and C, C, C and C strips of suitable fabric such as canvas placed to cover the entire margin of the skin. Prior to the placing on of these strips the skin is set out with a suitable tool and then the strips C, C, C and C are successively placed in position. As will be noted these strips are of suflicient width to cover all portions of the irregular contour of the skin and to overlap the same for a short distance. The strips are then firmly worked down against the skin and the board which on account of the adhesive material will completely seal the margin of the skin and will hold it in position on the board until dry. It will be also noted that the adhesive material does not come in contact with the grain face of the skin and only contacts with a small portion of the back of the skin, therefore no detrimental effect follows the use of the adhesive.

After the skin is mounted upon the board as just described, it is subjected to the drying process, at the completion of which the strips are peeled oif and the skin removed from the board.

What I claim as my invention is:

1. In a process of manufacturing leather the step which consists in setting out the wet skin, free from mucilaginous material, upon a drying board and sealing the margin of the skin to the board.

2. In a process of manufacturing leather the step which consists in setting out the wet skin free from mucilaginous material on the drying board, placing a retaining fabric over the marginal portions of said skm and thereby sealing the same to the board.

3. In a process of 7 manufacturing leather the step which consists in setting out the wet skin upon a drying board, placing an adhesive impregnated fabric over the marginal portions of said skin to seal the same to the board.

4. In a process of manufacturing leather the step which consists in setting out the Wet skin upon adrying board, placing a strip of adhesive impregnated fabric so as to overlap the marginal portions of the skin and the board beyond the same to thereby firmly attach the skin to the board during the drying process;

In testimony whereof I affix my signature.

' JOHN P. TOOLE. 

